Piano string



May 22, 1956 R. E. JOHNSON PIANO STRING Filed March 18, 1953 INVENTOR.

United States Patent O PIANO STRING Robert E. Johnson, Chicago, Ill.

Application March 18, 1953, Serial No. 343,196

3 Claims. (Cl. 84-199) This invention relates to a piano string having a covering Wire wound tightly thereon, and to the process of making such a device. More particularly, it relates to a piano string of the character described which has at least one end of the covering Wire firmly secured to the core Wire by distorting a plurality of turns of the former to form a tapered end thereon. Likewise, this invention relates to the process of forming a piano string of the character described, which process incorporates the step of distorting a plurality of turns on at least one end of the covering Wire by swaging, or the like, in order to form a tapered, gripping end on the covering Wire. This process is the subject of applicant's co-pending application entitled Process of Making Piano String Serial No. 557,795, filed January 6, 1956.

When the conventional process of manufacturing by hand piano strings having a covering Wire wound on a core Wire is utilized, one end of the covering Wire is not firmly secured to the core Wire. Such a condition will very often result in 'rattles and "buzzes in the piano string after it has been installed, since the end of the covering Wire is likely to vibrate independently of the core Wire.

In the improved method of winding a piano string of the Character described, which is the subject of this invention, the end of the core Wire adjacent the hitch-pin end of the Wire is firmly secured to the core Wire. This end of the covering Wire is pressed into the core Wire by a suitable tool, and at the same time, the core Wire and covering Wire are rotated. This results in this end of the covering Wire being firmly seated on the core Wire. However, in this conventional, manual method of winding, the opposite end of the covering Wire (adjacent the tuning pin end) is not firmly secured in this manner, but is merely left in the position it assumes after the excess covering Wire is separated therefrom by a quick bending or a breaking motion. This breaking movement of the covering Wire has a tendency to raise the last few turns of the covering Wire slightly so that they are not in firm contact With the core Wire. This method of removing the excess covering Wire not only has a tendency to produce the undesirable results described after installation of the Wire, but also is very likely to leave rough or sharp projections at this end of the piano string. These, in turn, may cause abrasions or cuts on the hands of an individual installing such a string. Likewise, such a condition detracts from the appearance of the string.

It is therefore an object of this invention to provide a piano string and a method for producing the same, which string has a covering Wire thereon terminating in a taper at at least one end.

Another object is to provide a piano Wire of the character described in which at least one end of the covering Wire has been distorted by causing the material in a plurality of turns at that end to flow so that a tapered end is formed in the covering Wire.

Yet another object of this invention is to provide a 2,746,335 Patented May 22, 1956 ICC piano Wire which has no rough or sharp projections at the ends of the covering Wire, which may cause injury to the hands of an individual handling such a Wire.

Another object is to provide a piano string of the character described which has a greatly improved and finished appearance.

Still another object of this invention is to provide a new and improved process of forming a piano string of the character described which includes the step of causing the material in a plurality of turns at one end of the covering Wire to flow so that a tapered end is formed in the covering Wire.

Further objects and advantages of this invention Will become evident as the description proceeds and from an examination of the accompanying drawing which illustrates one embodiment of the invention and in which similar numerals refer to similar parts throughout the several views.

In the drawing:

Figure 1 is a view in elevation of one form of piano string embodying the invention;

Figure 2 is an enlarged fragmentary view of a portion of the piano string shown in Figure 1 showing in greater detail one end of the covering Wire; and

Figure 3 is an enlarged fragmentary view in Vertical cross section of the same portion of the piano string shown in Figure 2.

Referring now to Figure 1, one form of piano string embodying the invention is shown therein, indicated generally by the numeral 1G. The complete piano Wire 10 is made up of a core Wire 12, an undercovering Wire 14, and a covering Wire 16. The undercovering Wire is in the form of a winding disposed on the core Wire and the covering Wire is in the form of a winding disposed on top of the undercovering Wire and extending slightly beyond onto the core Wire 12, at each end. One end of the core Wire 12 has a loop 18 formed therein, this end of the Wire 10 being generally known as the hitch-pin end. The opposite end 20 of the core Wire preferably terminates as a straight extension of the core Wire 12 and is generally known as the tuning pin end.

In the conventional winding process, the loop 18 is formed in the core Wire and the latter is then inserted in a suitable winding machine capable of rapidly rotating the core Wire. The undercovering Wire 14 is then wound on the core Wire 12 by first looping the end therof through the loop 18 of the core Wire and then rapidly rotating the core Wire so as to Wind the undercovering Wire 14 tightly thereon, beginning at a suitable point in spaced relation to the loop 18.

After the undercovering Wire 14 is so wound on the core Wire 12, the excess Wire at the ends can be removed by cutting or breaking away the unwound portions. A covering Wire 16 is then applied in substantially the same fashion so that it is wound throughout its length, eXcept at its ends, over the undercovering Wire 14, as best shown in Figures 2 and 3. A shoulder 22 is formed at the point Where the covering Wire extends beyond the undercovering Wire.

The end of the covering Wire which is adjacent the loop 18 in the core Wire 12 and is indicated generally by the numeral 24 normally may have the unwound excess removed therefrom by the use of a suitable cutting tool, which tool is rotated in the direction opposite to the direction of winding during the cutting operation so as to cause the end of the covering Wire to tightly grip the core Wire. In removing the excess Wire at the opposite end of the covering Wire, indicated generally by the numeral 26, however, the separation of the excess from the wound portion is normally accomplished by a quick bending or breaking movement of the Wire, as previously mentioned.

In its prcferred form, the process, which is the subject of this" invention, incorporates the step of causing the metal in a plurality of turns at the end of the covering Wire 16 to floW to form a tapered end on the covering Wire.

produce such a flow can, of course, be utilized. Since the'tuning pin end of the piano string, shown in Figure.

Vthe Work piece so that a plurality of successive blows are struek around the circumference thereof.

Upon insertion of the tuning pin end 20 of the piano string into such a rotary swaging machine in operation, and upon the application of a small amount of longitudinal pressure to the string in the direction of the machine, the end turns of the covering Wire are caused to fiow into substantally the form best shown in Figures 2 and 3.

The consecutive activation of the individual dies, around the circumference of the complete die assembly, as previously described,l should be made to coincide With the direction of the turns of the covering Wire. This is desirable since When a rotary swaging machine of the character described is utilized, there is a slight directional character to the impact of each individual die With a resuitant tightening or loosening of the individual turns. Obviously, it is desirable to have the impacts directed in such a fashion that they Will tend to further tighten the end turns 28 of the covering Wire rather than to loosen them.

The primary result of this swaging process is therefore to cause the metal end turns of the covering Winding 16 to flow in such a Way that the individual turns are Widened and compressed into the form of a conical taper. In other Words, each turn is flattened an increased amount toWard the end of the Winding until the outer extremity ofthe last turn 30 is only slightly larger in diameter than the core Wire itself. This flattening of'the end turns therefore actually also elongates the end of the covering Wire Winding;

Obviously, a conical taper Will normally be formed When using a rotary swaging machine of the Character described, but the invention is not meantto be limited to a piano Wire having this conical form of end on the covering Wire, or to a process for forming only this type of Wire. Likewise, suitable means other than a rotary sWaging-machine can, of course, be used to accomplish the distortion described of the end turns of the covering Wire. For example, the material in theV end turns of the covering Wire could be caused to fiow by pressing or rolling, as Well as by hammering, and conceivably other means of applying force to distort the turns might be devised. The primary purpose of the distortion of the end turns is, of course, to tightly compress the end turns 28 of the covering Wire 16 against the core Wire 12 regardless of the exact form, imparted to these turns.

To aid in securing the end turns of the covering. Wire This flowing, ofr distortio'n,ofthe'metal in thesel end turns 28 of the covering Wire can'best be carried outl by a swaging operation, although any method'which Will 16 to the core Wire 12, it has been found desirable to slightly fiatten' the'portion'of the core Wire which is associated therewith. For example, the fiattening of the core Wire at the point 32 provides a means for insuring that the end turn 24 does not slip circumferentially on the core Wire 12. A similar flattening of the core Wire under the end turns 28 of the covering Wire at the tuning pin end is also desirable and accomplishes the same result.

The end result of the utilization of the process described above is the formation of a piano string in which at least one end of the covering Wire has the form and disposition described in detail above, which improves both the appearance, handling properties, and actual functioning of the piano string. These results are obtained by distorting the turns of the covering Wire adjacent the end Without removing any of the material making up such turns, but merely causing them to fiow into a tightly formed, tapered end which grips the core Wire securely and positively.

Although the fiowing in the manner described of the turns at only one end of the covering Wire has been described, obviously the same sort of distortion could be carried out With respect to the turns at the opposite end though specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation. Changes in form and in the proportion` of parts, as Well as the substitution of equivalents are contemplated, as circumstances may su'ggest or render expedient, without departing from the spirit or scope of'this invention as further defined in the following claims.

It is claimed:

1. A piano string comprising a core Wire and a covering Wire Wound thereon in a plurality of contiguous turns, the turns adjaeent at least one end of said covering Wire being flattened to form a tapered end on said'covering Wire in tight engagement With said core Wire.

2. A piano string comprising a core Wire and a covering Wire Wound thereon in a plurality of contiguous turns, the turns adjacent at least one end of said covering Wire being flattened so that said end of said covering Wire tapers to a substantally reduced diameter.

3. A piano string comprising a core Wire and a covering Wire Wound thereon in a plurality of contiguous turns, the turns adjacent at least one end of said covering Wire being' flattened by the application of sufiicient compressive force to form a c'onical tapered end on said covering Wire in tight engagement With said core Wire.

References Cited in the file of this patent UNITED STATES PATENTS 776,737 Greenfield Dec. 6, 1904 2,049,769 Gray Aug. 4, 1936 2,1l2,988 Gould Mar. 22,v 1938v 2,375,068 Bennett May l, 1945 2,641,949 Jensen Inne 16, 1953 FOREIGNV PATENTS 593,066 France Aug. 17, 1925 

